Why aren't travellers mentioned in the hadeeth, “Jumu’ah prayer is an obligatory duty for every Muslim except four”?

''Friday Prayers'' :-:->
In a hadeeth of the Messenger (blessings and peace of Allah be upon
him) it says: "Jumu'ah prayer is an obligatory duty for every Muslim
except four." Why is it that travellers not included among those for
whom Jumu'ah prayer is waived in this hadeeth?.
Praise be to Allaah.
The hadeeth referred to inthe question was narratedfrom Taariq ibn
Shihaab (may Allah be pleased with him), that the Prophet (blessings
and peace of Allah be upon him) said: "Jumu'ah prayer is an obligatory
duty for every Muslim, to be offered in congregation, except four:a
slave who is owned, or woman, or a child, or one who is sick."
Narrated by Abu Dawood (1067). Al-Nawawi said in al-Majmoo' (4/483):
Its isnaad is saheeh according to the conditions of the two shaykhs
(al-Bukhaari and Muslim). Ibn Rajab said in Fath al-Baari (5/327): Its
isnaad is saheeh. Ibn Katheer said in Irshaad al-Faqeeh (1/190): Its
isnaad is jayyid. It was classed as saheeh by al-Albaani in Saheeh
al-Jaami' (3111).
It was narrated from Ibn 'Umar (may Allah be pleased with him) that
the Prophet (blessings and peace of Allah be upon him) said: "The
traveller is not obliged to pray Jumu'ah." Al-Haafiz said in Buloogh
al-Maraam: Its isnaad is da'eef.
The exception of the traveller is also mentioned in a number
ofhadeeths, including the hadeeth of Abu Hurayrah, according to which
the Prophet (blessings and peace of Allah be upon him), who said:
"There arefive for whom Jumu'ah is not obligatory: the woman, the
traveller, the slave, the child and the people of the wilderness."It
says in Majma' al-Zawaa'id: It was narrated by al-Tabaraani in
al-Awsat and its isnaad includes Ibraaheem ibn Hammaad, who was
classed as da'eef (weak) by al-Daaraqutni. Shaykh al-Albaani (may
Allah have mercy on him) said: (He is) da'eef jiddan (very weak).
It is no secret that the shar'i rulings should be derived from all of
the hadeeths that were narrated concerning this specific subject, and
they should not be derived from only one hadeeth whilst ignoring the
rest ofthe hadeeths.
The Prophet (blessings and peace of Allah be upon him) mentioned a
number, as we see in the hadeeth being asked about here, and
mentioning a number does not necessarily meanthat it is limited to
this number. The aim may have been to make it easier to remember this
hadeeth for those who heard it. A similar example is the words of the
Prophet (blessings and peace of Allah be upon him): "There are seven
whom Allah will shade with His shade on the Day when there will be no
shade but His…" By compiling all the hadeeths which speak of this
great matter ("Allah will shade them with His shade") it becomes clear
that there are more than 20 such categories, not only seven.
Al-San'aani said in Subul al-Salaam:
We can see from the hadeeths that Jumu'ah is not obligatory for six
people: children, as there is consensus that Jumu'ah is not obligatory
for them;slaves, as there is consensus on this matter except for
Dawood; women, and there is consensus that it is not obligatory for
them; sick people; travellers, who are not obliged to attend it; and
the sixth category, which is the people of thewilderness. End quote.
And Allah knows best.