Actually, back in the day, Synchros were way easier to spam and summon powerful copies of. When even Goyo / Brio / Trish were allowed (not to mention the legendary DARK DIVE BOMBER - er Dark Strike Fighter), Synchro decks thrived. However, most of them have been killed off due to various limitations (Plant Synchro and Debris/Synchron got hit hard, Blackwings got neutered, Mind Master got banned, et cetera) and so we have the somewhat tamer (?) Xyz monsters.
Constellar are actually a pretty cool archetype. They're no more Xyz spam than Verz are; basically, toolbox for stuff and generate advantage through Xyz. I find them quite tolerable and interesting; they have a built-in Infestation Pandemic Infection as well as a bunch of assorted cool toys (Pleiades = CED, Ptolemy M7 = awesome, very free Stratos, semi-free Salvage, and access to Starliege Paladynamo, among other things). I've had a spot in my heart for these guys ever since they were first released (without Sombre or Tenki/Bear), so I might be a bit biased, but... their theme is Xyz summoning, you know >>