In fairness, the guy might have been honestly feeling like he was saving you from future disappointment. In our current market trend towards long range shooting, the Grendel doesn’t keep up with the big kids on the playground. The Grendel might be the best option for long range shooting out of a 2.26” AR mag, but it’s a slouch against short action cartridges. And your Billy Bob at the gun counter - on average - is used to talking to someone buying their first gun, so his advice is likely jaded towards newbies who will be disappointed when their 6.5 Grendel won’t keep up with his buddies’ 6.5 Creedmoor at the range.
I’ve given the same advice to many new shooters - if you want into long range shooting, bypass the Grendel. I absolutely love the Grendel, and I’m really excited about trying out some 6mm variants, but a guy needs to realize the difference between the Grendel and a 2.8-3.0” 6 or 6.5mm cartridge at 1,000yrds before they go jumping in. As I expect is the case here.
But if a guy wants a low powder use, low recoil, moderately capable bolt gun, the Grendel is a great option. I would pick up the CZ 527 Varmint in the new PTR stock. The Howa is a great little rifle, but the CZ is a cut above. My Grendel’s are AR’s, but i’m Itching badly to get a 6mm Grendel variant in the CZ.