Far from it. I've found Relasine's posts to be largely devoid of fanboyism. He doesn't make the claim that PP is better in all respects. He mentioned one of the reasons that GW gets so much negative attention is that they do a number of things to garner that negative attention. PP, in contrast, does less that inspires wrath among its player base. Not that one company is objectively better than the other, but part of the reason for the continual butting of heads.
Honestly, now. This smacks more of fanboyism than anything Relasine posted.
Large target, I'm afraid. GW is still the monolith towering over the market and that makes it an easy target.
I always felt that fanboyism is about justifying the investment you made to yourself. You invest in a game system, be it wargaming or console gaming, or even PC gaming - it's financial at first, and then after a while investing time and effort, it becomes emotional. People look at what other systems offer, and theirs doesn't, and start to get a 'grass is greener' vibe. They present arguments to themselves about why their system is best, and thus why any shortfalls they have to experience are simply a consequence of having the best. If for some reason the fanboy switches 'teams', they're likely to be vitriolic regarding their original system because they regard the time, money, effort, and emotional investments they made in their original system as wasted. This is more common in mono-system or mono-company gamers who have limited funds. The most jovial and un-fanboy like gamers I've met are old guys who have an army for EVERYTHING, and regard all of their investments as worthwhile.
As far as the GW v. PP thing goes - I agree with most of Relasine's posts. GW is a big company, it's been around for a while, and has made a number of mistakes that angered it's fanbase. PP's smaller, has had less time to make mistakes, and tried to keep itself from making the same mistakes GW made. They're currently benefiting from being smaller, younger, and seeing what to do and what not to do in following GW's footsteps. Not to to say PP is a better company - but that for some, the perception is that it's better, because it's actively avoided old mistakes, and it hasn't been around long enough to commit more than a few brand new ones (supply issues!). I'm sure if we give PP another 10-15 years, there will be more player resentment, and more issues that crop up.
At least that's my view on the issue.