would not have big effects for bitcoin but what will happen if no treade, it means no people who hype , no PnD group , No ICO ,no bounty  , i think that what make altcoin is unique for bitcoin

It will be boring, the fun will not be there, just imagine the craziness that surrounds Zcash launch when the price was above 300BTC

Its  not  only  300  btc  but a whooping price  of  3300  btc  which is  really insane   for an  altcoin,  the  hype  goes  up to  high  which causes  for the  price to be  like  this  but as expected  it  would   really dump as  hard as you can  imagine and  now  it really happens because the price  now  is  0.02  btc  ,, sorry for those  investards  who  bought  on  expensive  price  points. Bitcoin  without  altcoin could  able  to happen  because  bitcoins is  the  father of all cryptos,  doesnt  affect at all.

If there's no altcoin and only bitcoin,then bitcoin will be more  stronger than what we are seeing now,holders and traders will be much more focus on Bitcoin compare when there are other crypto currency .

I dont know what bitcoin would be or become without altcoins, even maybe it being possible stronger, sure some altcoins does damage crypto world while others just bring more inovation.

If there were no other crypto currencies I think the price of bitcoin will be more stable since people could not try to ride a rising in the price of bitcoin so easily, besides I think a lot more people will hold their coins and that may cause the price to go higher than it is right now.

I think the price of bitcoin is not too high like this current price because alt coin really have big impact on the demand of bitcoin for the trading method that are most of the user doing this method.

i think if only trade bitcoin into fiat it will be boring because we know fiat price can't get pumped or dumped very hard , but different with altcoins

If bitcoin no other alternative may bitcoin coin will not have a rival. Because bitcoin and other alternative coin is a competitor who continues to want to be better. If bitcoin without coin other alternatives may not be good, because it is definitely bitcoin has no rivals so it is difficult to develop.

I doubt even if bitcoin hasnt competition it wouldnt improve, augur and zcash were made to put bitcoin into another level, besides that there is the issue of blocksize and when the mines ends how the system will work, some say the fees will be the rewards to the miners.