Totally agree with you there. There are definite advantages to an LCD arcade screen that make them a more compelling alternative to "true" CRTs in my opinion - and take this from someone who has used both.
Reasons:
1) They typically support much higher resolutions, which obviously are not used by most of MAME's games; however vector games are MUCH better looking, and game art, such as that provided on Mr. Do's artwork website, are so sharp you'd swear you could peel them off the monitor. After all, game artwork providing tips or special moves sometimes gave people the advantages they needed to survive in the arcades - so why deprive ourselves of that?
2) They have a much higher MTBF than CRTs, so they last far longer. I'm not sure where the previous comment regarding low LCD lifetimes came from, but perhaps that was based on older LCD technology that definitely had lower lifetimes.
3) They are lighter, safer, and have a much smaller profile allowing for more innovative and practical cabinets to be created, along with original designs.
4) They support more modern, advanced digital interfaces such as DVI, HDMI and DisplayPort; whereas CRTs rely on VGA which is (finally) being phased out by most computers/notebooks.
5) They are easier on the eyes, which is especially important for arcade gaming considering how close from the screen you stand.
6) They use far less power, and don't "burn-in" so you can leave them on in attract modes for extended periods of time without any concerns.
Also, the myth is definitely out there that LCDs don't look great due to their low refresh rate etc., but in my experience anything produced over the last three years looks perfectly fine, certainly competitive with CRT. Think about it - LCD displays are the only ones you see being used with the latest console and PC games like Crysis and Gears of War - and do those games look like crap? Also, newer LCDs (particularly LED-lit vs. CCFL-lit) are MUCH brighter than CRTs.
I hate to disagree with my esteemed colleagues on this site, but I don't think the resolution issues of an LCD are much of a problem. If there are any possible issues with LCD technology, it's that they expose the imperfections of the original game resolutions more than a CRT, as the latter "hides" these issues better. However, with the use of filters such as those provided by MAME, that can be mitigated - though I don't believe you'll ever reach "true" perfection. It's akin to the old "record album vs. cd" debate - yes, there's a certain quality to records that you can't reproduce with CDs, but the advantages of CDs proved they were overwhelmingly better with all things considered.
I think the future will show that companies like Billabs, Wells Gardner and others will stop supporting CRT technology altogether and move exclusively to LCD. These companies in the past have supported CRTs into the 21st century since many arcade cabinets were still being produced with this technology; however current arcade, gambling and bartop games are pretty much exclusively LCD as the price point has dropped to a reasonable level. These companies will no longer continue to offer CRT as an option just to satisfy a small community such as ours. So in short - LCD technology, learn it, love it, use it - cuz you gotta. ;-)
Shoegazer