The Memphis can grill very well with no mods I can assure you. I could get sear marks almost as good as my RED without a flame zone or grill grates by just leaving in the drip pan. But the price point on the Memphis is higher and might not be a big box item that Lowes or Home Depot would take a chance on being the name is not well known.
Weber is a mid grade to high grade name. Their name is known for quality, well made grills. The top of the line gasser is well over $1,000 and sells well.
A pellet grill can be made to grill if it is able to reach higher temps with a combination of insulation/double wall design, thick grates, and high quality metal parts that will not warp/bend due to the excessive heat. A flame zone insert with a controller that works with that function is also a must.
Most people in general are not fanatical I mean passionate like us about smokers and grills. I own way more cooking equipment than your average person. To reach that other consumer will require a quality replacement to their gasser that is also a green alternative. Something that men will gather around during a party and salivate over then tell their SWMBO that they want one too. I have a friend at work who had never heard of a pellet grill a year ago and I talked him into buying a Traeger. Now he went halves with me on a load of pellets and is looking at getting a larger grill now. What really got him interested was the Costco road show with Traeger. After seeing the grill in person and talking with me he was hooked. I made him understand how it works and what to expect. I too got a pellet grill after constantly seeing the great cooks on them at other forums.
It is nice to see these cheaper models go mainstream but again with their controllers and design people will try to use them as a grill and be dissatisfied with the results. Like a really fast looking car that cannot get out of it's own way. Because it looks like a grill and not a traditional smoker people will expect them to "act" like a grill too. So I really don't see these things going too far with the general public.