For me it comes down to space and cash.
I recently need to pay off my CC a bit, so I sold my 1/60 MAX FAST pack toy. After all, I have the 1/48. so what did i need the 60 for? If i can get myself a Roy 1/48 with the strike set, then ill more than likely sell my 1/60 of him as well.
Lets face it, here in oz, to get something like the low viz or max 1/48 i had to fork out over $350 each! Thats a lot of money I could be spending on the various other toy series i collect for one thing, like transformers and Marvel Legends. Theres only so much I can do and spend, and macross is just to pricey to do hardcore.
Also Yamato (Who I think make the best valks) just arent doing anything new. Yeah theres the Qraus, but im so-so on getting them. Again, they're like $250 or so each for me, so its a big call. The monster is laughably expensive, so Ill skip that. And the mO stuff looks silly. So thers just nothing left to get! I havent posted here in quite some time, bu Id swing by looking for new stuff....and theres nothing.
So with a roy 1/48 and an Alpha fighter i think Ill be done for quite some time. Sad really.