Any better motion picture sooner or later gets own merchandise, usually released either by the producer itself, or by outside companies willing to earn on fandom demands. Garfield isn't an exception - PAWS Inc. maintains network of online stores accessible from this page https://garfield.com/shop , where various items are offered for sale. The offer addressed to us, fans is quite rich: from comics books and cartoon files to animated cels, original Jim Davis artworks, calendars, postcards, outfits promoting the franchise and even pet bowls.
Certain products from the offer tend to contradict comics strips and motion pictures canon - notable examples are merchandise apparently designated as wedding gifts and presents for spouses, such as: platters, matching mugs or postcards presenting Arlene and Garfield as loving couple. Those items oppose stance presented in comics strips, notably Arlene's premiere appearance in December 1980 https://garfield.com/comic/1980/12/18 , where the pink kitty did predict their relationship being "tenuous". Non-native English speakers may don't know meaning of the word "tenuous", thus I decided to write it from the dictionary:
tenuous - adj. 1. not dense: rare (~fluid) 2. not thick, slender (~ rope) 3. having little substance: flimsy, weak (~influences, relationship) 4. lacking stability, shaky (~ reasoning, ~ relationship).
Further check-up of the synonym adjectives will lead to conclusion, that Jim Davis apparently designed the relationship between Garfield and Arlene as on- and off-going. 37 years after her debut, the relationship maintains the unstable character, matching Garfield's ego.
The reason mentioned above merchandise depicts those two as loving couple should be self-explanatory: promoting marriage requires depiction of a couple in healthy relationship, only few newly-married spouses would accept gifts mocking their relationship and PAWS Inc. management must be aware of that. Same with gifts oriented towards children and families - even people from not-the-healthiest families will not rather welcome products advertising hostile relationships. Also, Arlene had been picked for those merchandise mostly because she is best known female from Garfield universe - I can tell from my online experiences, that many American people do not remember Garfield and Friends well enough, so they automatically (and correctly) identify Arlene as Garfield's second half.
Some time ago we had minor incident here, when certain users put opposing edits about characters http://garfield.wikia.com/wiki/Thread:22040 ; supporting stance of another fellow advocate of cartoon/comics canon triggered the same individual, who remains himself in ongoing conflict with me just because I dared to question parts of his personal opinions. Quite predictably, I have been accused of assault upon official PAWS Inc. merchandise over here http://garfield.wikia.com/wiki/Thread:22040#5 in line "And don't try to act like Arlene and Garfield are never nice to each other or doesn't have interest in each other."
But the most ludicrous part is that the author of this lovely assumption personally enjoys anti-capitalist propaganda presented by Rune Andreasson and Seth MacFarlane (also known to attack traditional moral values), which somehow doesn't disturb him being fond of media his idols are opposing. In short, capitalist anti-capitalist.
Such people are nonetheless necessary, since someone has to buy products of Jim's hard labor allowing PAWS Inc. employers living for their own. This is pretty much the way capitalism works.