Development is taking way too long.
Is that being fair? Not only is this open source software, but hardening LN against all edge cases is no easy feat. I'm also worried that massive amounts of coins will move into LN upon launch of publicly available wallets. Developers need to take the utmost care to ensure that coins aren't lost interfacing with LN.
Market share vs. altcoins doesn't matter. That's the wrong approach. "Move fast and break things because X or Y coin developers move quicker" isn't reasonable. Has Lightning been integrated into an altcoin? If not, why not?
Once LN is widely deployed, Bitcoin is likely to regain significant market share from any coin whose value is derived from fast/cheap transactions.